1. Field of the Invention
The present invention is directed to a regenerative burner, burner system and method of burning using regenerative burners which comprises a fuel supply section with its tip opening into a furnace provided along the burner axis; a flame stabilizing section, provided at the tip of the fuel supply section; a room temperature air supply section with its tip also opening into the furnace, provided around the fuel supply section; plural pre-heated high temperature air supply sections with their tips opening into the furnace, provided around but apart from the fuel supply section; and heat storage material, upstream from the tip of the pre-heated high temperature air supply section.
2. Description of Related Art
A conventional regenerative burner has an integrated structure consisting of a combustion section 20 and a regenerative section 21. A pair of regenerative burners having this structure are installed in a furnace 22, for alternate selective combustion as shown in FIG. 1. In the burner, air passes through the regenerative section where it is pre-heated. When the exhaust gas passes through the regenerative section the heat is stored, to be used in turn to pre-heat the intake air. This results in the recovery of waste heat, thereby achieving a high degree of thermal efficiency.
The regenerative burners shown in FIG. 1 require that the combustion sections and the regenerative sections of the burners be lined with a refractory material for heat insulation, since they are subject to the flow of high temperature exhaust gas and the generation of high temperature flames. Furthermore, since the fuel supply sections are also exposed to high temperature at their tips, they deteriorate due to high temperature oxidation. To avoid this, air cooling or water cooling must be used. Moreover, the complicated and large structure of the entire apparatus increases the overall furnace equipment cost, and combustion in the presence of pre-heated high temperature air significantly increases NOx (nitrogen oxide) emissions.